diff -r 000000000000 -r f90c822e73f8 src/share/vm/code/icBuffer.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/code/icBuffer.cpp Wed Apr 27 01:25:04 2016 +0800 @@ -0,0 +1,236 @@ +/* + * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "code/codeCache.hpp" +#include "code/compiledIC.hpp" +#include "code/icBuffer.hpp" +#include "code/nmethod.hpp" +#include "code/scopeDesc.hpp" +#include "gc_interface/collectedHeap.inline.hpp" +#include "interpreter/interpreter.hpp" +#include "interpreter/linkResolver.hpp" +#include "memory/resourceArea.hpp" +#include "memory/universe.inline.hpp" +#include "oops/method.hpp" +#include "oops/oop.inline.hpp" +#include "oops/oop.inline2.hpp" +#include "runtime/mutexLocker.hpp" +#include "runtime/stubRoutines.hpp" + +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC + +DEF_STUB_INTERFACE(ICStub); + +StubQueue* InlineCacheBuffer::_buffer = NULL; +ICStub* InlineCacheBuffer::_next_stub = NULL; + +CompiledICHolder* InlineCacheBuffer::_pending_released = NULL; +int InlineCacheBuffer::_pending_count = 0; + +void ICStub::finalize() { + if (!is_empty()) { + ResourceMark rm; + CompiledIC *ic = CompiledIC_at(CodeCache::find_nmethod(ic_site()), ic_site()); + assert(CodeCache::find_nmethod(ic->instruction_address()) != NULL, "inline cache in non-nmethod?"); + + assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer"); + ic->set_ic_destination_and_value(destination(), cached_value()); + } +} + + +address ICStub::destination() const { + return InlineCacheBuffer::ic_buffer_entry_point(code_begin()); +} + +void* ICStub::cached_value() const { + return InlineCacheBuffer::ic_buffer_cached_value(code_begin()); +} + + +void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) { + // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we + // store the location of the inline cache. Then we have enough information recreate the CompiledIC + // object when we need to remove the stub. + _ic_site = ic->instruction_address(); + + // Assemble new stub + InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr); + assert(destination() == dest_addr, "can recover destination"); + assert(cached_value() == cached_val, "can recover destination"); +} + + +void ICStub::clear() { + if (CompiledIC::is_icholder_entry(destination())) { + InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value()); + } + _ic_site = NULL; +} + + +#ifndef PRODUCT +// anybody calling to this stub will trap + +void ICStub::verify() { +} + +void ICStub::print() { + tty->print_cr("ICStub: site: " INTPTR_FORMAT, _ic_site); +} +#endif + +//----------------------------------------------------------------------------------------------- +// Implementation of InlineCacheBuffer + +void InlineCacheBuffer::init_next_stub() { + ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size()); + assert (ic_stub != NULL, "no room for a single stub"); + set_next_stub(ic_stub); +} + +void InlineCacheBuffer::initialize() { + if (_buffer != NULL) return; // already initialized + _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer"); + assert (_buffer != NULL, "cannot allocate InlineCacheBuffer"); + init_next_stub(); +} + + +ICStub* InlineCacheBuffer::new_ic_stub() { + while (true) { + ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size()); + if (ic_stub != NULL) { + return ic_stub; + } + // we ran out of inline cache buffer space; must enter safepoint. + // We do this by forcing a safepoint + EXCEPTION_MARK; + + VM_ForceSafepoint vfs; + VMThread::execute(&vfs); + // We could potential get an async. exception at this point. + // In that case we will rethrow it to ourselvs. + if (HAS_PENDING_EXCEPTION) { + oop exception = PENDING_EXCEPTION; + CLEAR_PENDING_EXCEPTION; + Thread::send_async_exception(JavaThread::current()->threadObj(), exception); + } + } + ShouldNotReachHere(); + return NULL; +} + + +void InlineCacheBuffer::update_inline_caches() { + if (buffer()->number_of_stubs() > 1) { + if (TraceICBuffer) { + tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs()); + } + buffer()->remove_all(); + init_next_stub(); + } + release_pending_icholders(); +} + + +bool InlineCacheBuffer::contains(address instruction_address) { + return buffer()->contains(instruction_address); +} + + +bool InlineCacheBuffer::is_empty() { + return buffer()->number_of_stubs() == 1; // always has sentinel +} + + +void InlineCacheBuffer_init() { + InlineCacheBuffer::initialize(); +} + + +void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) { + assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint"); + assert (CompiledIC_lock->is_locked(), ""); + if (TraceICBuffer) { + tty->print_cr(" create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT, + ic->instruction_address(), entry, cached_value); + } + + // If an transition stub is already associate with the inline cache, then we remove the association. + if (ic->is_in_transition_state()) { + ICStub* old_stub = ICStub_from_destination_address(ic->stub_address()); + old_stub->clear(); + } + + // allocate and initialize new "out-of-line" inline-cache + ICStub* ic_stub = get_next_stub(); + ic_stub->set_stub(ic, cached_value, entry); + + // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache + ic->set_ic_destination(ic_stub); + + set_next_stub(new_ic_stub()); // can cause safepoint synchronization +} + + +address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) { + ICStub* stub = ICStub_from_destination_address(ic->stub_address()); + return stub->destination(); +} + + +void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) { + ICStub* stub = ICStub_from_destination_address(ic->stub_address()); + return stub->cached_value(); +} + + +// Free CompiledICHolder*s that are no longer in use +void InlineCacheBuffer::release_pending_icholders() { + assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint"); + CompiledICHolder* holder = _pending_released; + _pending_released = NULL; + while (holder != NULL) { + CompiledICHolder* next = holder->next(); + delete holder; + holder = next; + _pending_count--; + } + assert(_pending_count == 0, "wrong count"); +} + +// Enqueue this icholder for release during the next safepoint. It's +// not safe to free them until them since they might be visible to +// another thread. +void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) { + MutexLockerEx mex(InlineCacheBuffer_lock); + icholder->set_next(_pending_released); + _pending_released = icholder; + _pending_count++; + if (TraceICBuffer) { + tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", icholder); + } +}